Carrier pucks are well known in the manufacturing and packaging industries. Their primary use is to support and stablize objects while moving along a production line. Carrier pucks are also very useful to protect fragile objects from collision during conveying.
A convenient way to convey carrier pucks is to move them in bulk between the stations of the assembly line. The main reason to convey puck in bulk is to allow the pucks to accumulate between each station. In doing this, the line can be kept running even though one or more stations are down because of jamming, repairs, or the like.
Bulk conveying is preferably done using round pucks. A round causes minimal surface contact to other similar pucks, minimizing friction and allowing bulk conveying while preventing jamming along the production line.
U.S. Pat. No. 4,664,248, entitled "Device and Method for Conveying and Orienting Randomized Circular Product-Carrying Pucks", issued to Goodman, Jr. et al. on May 12, 1987, discloses a generally round carrier puck. The round puck has two distinct outer contacting surfaces. A first surface which is round and toothed and a second slide surface which is cut flat in an arc of circumference. As the puck travels on the conveying surface it will encounter a toothed side guide which engages the toothed round portion of the puck thus imparting rotation of the puck until it reaches the flat surface which will stop rotation and cause the puck to slide forward in the direction of travel of the conveyor. A drawback of this arrangement is that the puyck can only be oriented in one preferred direction (or at 180.degree. from the preferred direction). Another drawback is that a pucks according to that invention cannot easily be spaced apart from one another.
U.S. Pat. No. 5,479,762, issued on Jan. 2nd of 1996 to Bliss and entitled "Carrier Puck", discloses a rectangular carrier puck having lateral ears which fit recesses in the conveyor belt. The ears-recesses system restrains the puck movement allowing the pucks to be correctly oriented and equally spaced along the conveyor. However, a major drawback of such arrangement is that it is unsuitable for bulk conveying.
U.S. Pat. No. 5,484,052, issued to Pawloski et al. on Jan. 16, 1996 and also entitled "Carrier Puck", describes a carrier puck having a rectangular base and a cylindrical top. The puck is shaped to receive either a first or a second article having different dimensions and shape. The rectangular base allows the puck to be oriented in four quadrants (90.degree. increments) by sliding on conveyor lateral guides. However, since the base in rectangular, it is not possible to know in which quadrant the puck is oriented with additional data. Such data is obtained by four recesses with one recess located in each quadrant of the cyclindrical sides of the puck allowing mechanical sensors mounted to a conveyor to sense when the puck is properly oriented to receive either the first or the second articles. An important drawback is the lack of control over the quadrant orientation of the puck. Once the puck is in a given orientation, it will continue that way.